Composite coated substrates and moldable composite materials

ABSTRACT

A moldable composite material contains flakes of composite material, i.e., flakes of polymeric matrix materials having fibers embedded therein. An improved substrate is provided by providing a substrate and applying a coating onto the substrate, the coating containing the flakes of composite material. A first construction member can be secured to a second construction member by applying the coating onto an attachment region of the first construction member, and applying a fastener onto the first construction member in the coated attachment region to secure the first construction member to the second construction member.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application No.61/039,825 filed Mar. 27, 2008, the contents of which are incorporatedherein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to hybrid materials that employ composites tocoat a substrate or form a moldable material.

BACKGROUND

Building materials, and other substrates, are often exposed to wear,sunlight, weather, and insects, causing the materials to deterioratequickly. The cost of wood, and other materials, has also increasedsignificantly in recent years. The desire to reuse or recycle materialsis also a greater focus in “green” building. In addition, traditionalbuilding materials sometimes exhibit insufficient mechanical propertieswhen exposed to high loads, for example, high winds or shock waves fromexplosive blasts. In such instances, where traditional buildingmaterials are employed, significant destruction, injury, and even lossof life are possible.

SUMMARY OF THE INVENTION

The present invention resides in one aspect in a moldable compositematerial that contains flakes of composite material.

The present invention resides in another aspect in a method for makingan improved substrate. The method is practiced by providing a substrateand applying a coating onto the substrate, the coating comprising flakesof composite material.

The present invention resides in yet another aspect in a method forsecuring a first construction member to a second construction member, byapplying a coating onto an attachment region of the first constructionmember, and applying a fastener onto the first construction member inthe coated attachment region to secure the first construction member tothe second construction member.

The invention also provides, in another aspect, an improved substrate.The improved substrate includes a substrate and a coating on thesubstrate, the coating comprising a plurality of flakes of compositematerial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic top view of a flake of composite material havingcontinuous, unidirectionally oriented fibers.

FIG. 2 is a schematic top view of a flake of composite material havingchopped randomly oriented fibers.

FIG. 3 is a side schematic view of a laminated flake of compositematerial.

FIG. 4 schematically illustrates a moldable composite material formedfrom substrate pieces and composite material flakes.

FIG. 5 schematically illustrates flakes of composite materialconcentrated around the periphery of a substrate.

FIG. 6 schematically illustrates flakes of composite materialconcentrated in rows on a substrate.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed in one aspect to a moldable materialcomprised of flakes of a composite material. A composite materialincludes fibers embedded in a polymeric matrix. Composite materials canoptionally be made in the form of sheets, continuous rolls or otherforms. To provide flakes, a composite material may be chopped, cut orotherwise divided into flakes that may have various lengths, e.g., about1 to about 6 inches (in.) [about 2.5 to about 15.25 centimeters (cm)]long, and various widths, e.g., about ¼ to about 3 in. (about 0.6 toabout 7.6 cm) wide. However, the present invention is not limited inthis regard as any practical flake size can be used.

In one embodiment, the moldable material includes a mixture of flakes ofcomposite material with filler. The filler may comprise flakes of anyone or more substrate materials, including, for example, buildingmaterials or other materials, such as wood, wood flakes, sawdust,plastic, metal, composites or textiles. The composite flakes may bemixed with substrate pieces or other filler so that the composite flakesare somewhat evenly distributed throughout the mixture. Adhesive canoptionally be included to bind the composite flakes with the substrateflakes. Alternatively, the composite flakes may be used withoutsubstrate flakes to form a moldable material. The moldable material maycomprise substantially free-flowing flakes or flakes that have beenconsolidated into a useful precursor form, e.g., pellets, by applicationof heat and/or pressure. When the matrix material in a thermoplastic, iftwo or more flakes are touching one another when exposed to sufficientheat and/or pressure the polymeric matrix materials therein can at leastpartially melt, thereby causing the matrix material to act as soon as anadhesive and the flakes to bond to one another.

In another embodiment, the invention provides an improved substrateachieved by applying a coating on a substrate, such as a constructionmember, the coating having been made from the flakes of compositematerial described herein. The substrate may comprise, for example,wood, plastic, metal, a plywood sheet, cut lumber, pressboard, particleboard, oriented strand board, etc., or a formed material such as ahoneycomb, or a combination thereof. The term substrate may include anytype of material and is not to be limited to the above disclosedmaterials.

In one embodiment shown in FIG. 1, a flake of composite materialgenerally designated at 10 includes a polymeric matrix 12 and aplurality of mutually longitudinally aligned fibers 14 located withinthe polymeric matrix. A flake, sheet, fragment, laminate or ply ofcomposite material may be characterized as “unidirectional” in referenceto the principally unidirectional orientation of the fibers therein, asseen in flake 10. In addition, while flake 10 is rectangular, thepresent invention is not limited in this regard as a flake of compositematerial can be any shape without departing from the broader aspects ofthe present invention. In addition, the fibers can be longitudinallyoriented in the polymer matrix, or chopped and randomly oriented in thepolymer matrix, or a combination thereof. For example, the flake 16shown in FIG. 2 is randomly shaped and comprises fibers 18 forming whichare chopped from longer strands and are randomly oriented in the polymermatrix 20. In addition, and rather than instead of the number of fibers,the composite material can employ particulate material.

Various types of fibers or particulate may be used in a compositematerial. Exemplary fibers include E-glass and S-glass fibers. E-glassis a low alkali borosilicate glass with good electrical and mechanicalproperties and good chemical resistance. This type of glass is the mostwidely used in fibers for reinforcing plastics.

S-glass is the higher strength and higher cost material relative toE-glass. S-glass is a magnesia-alumina-silicate glass for aerospaceapplications with high tensile strength. Originally, “S” stood for highstrength.

E-glass fiber may be incorporated in the composite in a wide range offiber weights and thermoplastic polymer matrix material. The E-glass mayrange from about 10 to about 40 ounces per square yard (oz./sq.yd.), forexample, 19 to 30 or, in a particular embodiment, 21.4 to 28.4oz./sq.yd.

Other fibers may also be incorporated, optionally in combination withE-glass and/or S-glass. Such other fibers include ECR, A and C glass, aswell as other glass fibers; fibers formed from quartz, magnesiaaluminosilicate, non-alkaline aluminoborosilicate, soda borosilicate,soda silicate, soda lime-aluminosilicate, lead silicate, non-alkalinelead boroalumina, non-alkaline barium boroalumina, non-alkaline zincboroalumina, non-alkaline iron aluminosilicate, cadmium borate, aluminafibers, asbestos, boron, silicone carbide, graphite and carbon such asthose derived from the carbonization of polyethylene, polyvinylalcohol,saran, aramid, polyamide, polybenzimidazole, polyoxadiazole,polyphenylene, PPR, petroleum and coal pitches (isotropic), mesophasepitch, cellulose and polyacrylonitrile, ceramic fibers, metal fibers asfor example steel, aluminum metal alloys, and the like.

One suitable organic polymer fiber is formed from an aramid exemplifiedby Kevlar. Other high performance, unidirectional fiber bundlesgenerally have a tensile strength greater than 7 grams per denier. Thesebundled high-performance fibers may be any one of, or a combination of,aramid, extended chain ultra-high molecular weight polyethylene(UHMWPE), poly [p-phenylene-2,6-benzobisoxazole] (PBO), andpoly[diimidazo pyridinylene (dihydroxy) phenylene] (M5). The use ofthese very high tensile strength materials is particularly useful formaking composite ballistic armor panels and similar applicationsrequiring very high ballistic properties.

Still other fiber types known to those skilled in the particular art towhich the present invention pertains can be substituted withoutdeparting from the broader aspects of the present invention. Forexample, Aramid fibers such as, inter alia, those marketed under thetrade names Twaron, and Technora; basalt, carbon fibers such as thosemarketed under the trade names Toray, Fortafil and Zoltek; LiquidCrystal Polymer (LCP), such as, but not limited to LCP marketed underthe trade name Vectran. Based on the foregoing, the present inventioncontemplates the use of organic, inorganic and metallic fibers eitheralone or in combination.

The quantity of S-glass, E-glass or other fiber in a composite materialmay optionally accommodate about 40 to about 90 weight percent (wt %)thermoplastic matrix, for example about 50 to about 85 wt % and in oneembodiment about 60 to about 80 wt % thermoplastic matrix in the ply,based on the combined weight of thermoplastic matrix plus fiber.

The polymeric matrix material may comprise a thermoplastic polymericmaterial (providing a “thermoplastic flake”), a thermosetting polymericmaterial (providing a “thermosetting flake”), or a combination thereof.A thermoplastic polymeric matrix may comprise a polymer that may be ahigh molecular weight thermoplastic polymer, including but not limitedto, polypropylene, polyethylene, nylon, PEI (polyetherimide) andcopolymers. Thermoplastic loading by weight can vary widely depending onphysical property requirements of the intended use of the product sheet.

Flakes used in the present invention can include flakes made exclusivelyfrom a single composite material, or the flakes can be made fromcomposite materials that differ from each other with respect to thefibers and/or with respect to the polymer matrix therein. For example, athermoplastic polymer, or a combination thereof are each differentmatrix materials from the other. In addition, one type of thermoplasticor thermosetting polymer matrix may be different from another type ofthermoplastic or thermosetting polymer matrix, respectively. Thus,thermoplastic polyethylene is different from thermoplasticpolypropylene, etc.

In one embodiment, the composite material is a laminate which includesat least one composite layer or ply, a composite layer being a singlelayer comprising a polymer matrix with fibers therein. Optionally, alaminate of two or more composite layers may contain composite layersthat differ from each other with respect to the fibers and/or withrespect to the polymer matrix therein. For example, the flake 22 shownin FIG. 3 is formed from a laminate of two composite layers 24 and 26.In the illustrated embodiment, each of the composite layers 24 and 26includes oriented continuous fibers 28. The fibers 28 in one of thelayers 24 and 26 are oriented substantially orthogonally to the fibersin the other layer. However, the present invention is not limited inthis regard as the fibers 28 in each layer can be oriented at any anglerelative to one another. In addition, the fibers in each layer can be ofdifferent material and can also be chopped, continuous, aligned,randomly oriented, and combinations thereof. While the flake 22 has twolayers, the present invention is not limited in this regard as anypractical number of layers of composite material may comprise the flakewithout departing from the broader aspects of the present invention.

The flakes 10, 16 and/or 22 can be accumulated into a moldable compositematerial which can be molded using standard molding techniques, e.g.,injection molding, blow molding, compression molding, film insertmolding, rotational molding, thermoforming, etc., to produce a moldedproduct 30 as shown in FIG. 4. Optionally, the molding process mayinclude the application of heat and/or pressure to cause adjacent flakes10, 16, 22 to at least partially melt or set, and bond to one another.Optionally, the moldable composite material includes fillers, processingadditives, etc. In one embodiment, as shown in FIG. 4, the flakes 10,16, and 22 are combined with pieces of substrate material 32 as fillerto provide the moldable composite material. The substrate pieces mayinclude for example, wood flakes, sawdust, metals, or any othersubstrate, and any combination thereof. The flakes 10, 16, and/or 22 aremixed with the substrate pieces 32 so the flakes are somewhat evenlydistributed throughout the mixture, which may then be molded into anydesired shape, for example, into a configuration having a semicircularcross-section as illustrated in FIG. 4. In one embodiment, an adhesivemay be added to the moldable composite material to improve adherencebetween the substrate material 32 and the flakes 10, 16, 22.

In another embodiment, the moldable composite material may be formedfrom one or more flakes 10, 16, and/or 22 and fibers, substantiallywithout substrate flakes or particles, and in another embodiment, themoldable composite material may be formed entirely from flakes 10, 16,and/or 22, substantially without additional fibers or flakes orparticles of substrate material or other filler.

In an alternative embodiment of the present invention, flakes 10, 12and/or 22 can be concentrated and/or additionally coated in particularareas of the molded product 30. For example, the flakes of compositematerials can be concentrated along edge portions or other regions ofthe molded product 30 as the addition of the composite material mayenhance the fastener retention properties, or other properties, of themolded product. In an alternative embodiment of the present invention,flakes 10, 16, and/ or 22 can be additionally coated in particular areasof the molded product 30.

In some of the above-described embodiments, the flakes 10, 16, and/ or22 can be formed from larger pieces of the composite material that aresubsequently chopped or otherwise cut into the flakes. If the fibersthat are in the composite material are oriented in a particulardirection, the flakes can also be positioned in the moldable material oron the substrate so that the flake orientation and thereby the fiberorientation enhances the mechanical properties of the coated substrateor moldable material.

According to another aspect, flakes of composite material may be appliedas a coating onto a substrate. As indicated above, the substrate may bewood, including lumber, metal, or any other members. In one embodiment,the substrate is a structural construction material such as plywood,framing lumber, panel board, etc. For example, as shown in FIGS. 5 and6, an improved substrate 34 is provided by applying a coating 36 onto asubstrate 38. The coating 36 is made from flakes 10, 16, and/or 22, isapplied onto selected areas of a substrate 38, in particular, along theperipheral edges of the substrate to provide a an improved substrate 34.The coating 36 may be applied onto the substrate 38 by rendering theflakes 10, 16 and/or 22 in a flowable form, e.g., as the moldablecomposite material, or in a paint-like suspension in a volatile carrierfluid, etc., and applying the flowable composition onto the substrate 38in the desired areas, an allowing the coating to congeal and/or cure.The coating 36 enhances the capability of the substrate 38 to retain afastener (not shown), such as, but not limited to a screw or a nail.Alternatively, and as shown in FIG. 6, an improved substrate 40 hascoatings 42 and 44 comprising flakes 10, 16 and/or 22 which are disposedin rows along the substrate 38 in areas where fasteners would normallybe placed.

The present invention is not limited to a coatings concentrated alongperipheral edges or in rows on a substrate. Rather, a coating of flakes10, 16, and/ or 22 can be applied over a variety of specific areas orover the entire surface of a substrate without departing from thebroader aspects of the present invention.

The coatings 36, 42, and/or 44 may be applied as single layers, but theinvention is not limited in this regard, and in other embodiments,various numbers of layers may be applied over the entirety or just aportion of the substrate. Optionally, discrete layers of flakes 10, 16,and/ or 22 on a substrate may be incorporated such that flakes of onetype comprise a first coating on a substrate, followed by differenttypes of flakes applied as a second coating on a substrate.

In other embodiments, it may be useful to coat the entirety of asubstrate 38 in a single layer of composite material, while addingadditional layers to areas requiring reinforcement. Furthermore, thecoating 36 can be applied so that the fibers therein are alignedrelative to one another in a particular direction. For example, oblongunidirectional flakes 10 having fibers aligned in the lengthwisedirection can be applied onto a substrate 38 in a manner that allows theflakes 10 to align with each other. Without wishing to be bound by anyparticular theory, it is believed that by aligning the fibers 14 in aparticular direction, the substrate should be strengthened in thatdirection.

Optionally, an adhesive may be added to the flakes 10, 16, and/ or 22 ina coating 36, 42 and/or 44, or in a moldable composite material, toimprove adherence between the flakes themselves (optionally includingsubstrate flakes 32) and/or between the flakes 10, 16, and/ or 22 and asubstrate 38 on which the flakes are disposed. In addition, if two ormore of the flakes 10, 16, and/ or 22 are touching one another, thepresent invention encompasses heat and pressure to cause the compositematerial to at least partially melt or cure, thereby causing thecomposite flakes to bond to one another to form a coating on asubstrate.

In some embodiments of the present invention, the flakes 10, 16, and/ or22 are used to form a layer of composite material coating substantiallyan entire substrate surface to the mechanical properties and durabilityof the overall substrate. Assuming the fibers in the flakes are paralleland longitudinally oriented, as in flakes 10, and depending on thedesired mechanical properties of the improved substrate, the flakes canbe oriented onto the substrate so that the fibers are substantiallyoriented in a particular direction.

One advantage of one embodiment is that substrate coating and themoldable material can utilize flakes 10, 16, and/ or 22 made from waste,recycled, or scrap composite material.

Another advantage of one embodiment of a composite coating and moldablematerial of the present invention is that the flakes 10, 16, and/ or 22can be employed to enhance the mechanical properties of the moldablematerial or coated substrate of the present invention. Theseenhancements can be overall and/or in desired areas and/or directions.

Still another advantage of the composite coating and moldable materialof the present invention is that the flakes 10, 16, and/ or 22, or acoating 36 thereof, can be concentrated in particular areas to enhancethe retention of fasteners, such as, but not limited to, screws andnails, thereby making the moldable material or coated substrate lesslikely to dislodge from a structure in severe weather or stressconditions.

The advantages set forth above are illustrative only and should not beconsidered an exhaustive list, as other advantages will be evident tothose skilled in the pertinent art to which the present inventionpertains.

The terms “a” and “an” herein do not denote a limitation of quantity,but rather denote the presence of at least one of the referenced item.

Although the invention has been described with reference to particularembodiments thereof, it will be understood by one of ordinary skill inthe art, upon a reading and understanding of the foregoing disclosure,that numerous variations and alterations to the disclosed embodimentswill fall within the spirit and scope of this invention and of theappended claims.

1. A moldable composite material comprising flakes of compositematerial.
 2. The material of claim 1, comprising first flakes of a firstcomposite material and second flakes of a second composite material, thefirst composite material being different from the second compositematerial.
 3. The material of claim 2, wherein the first flakes comprisefibers in a first polymer matrix and the second flakes comprise fibersin a second polymeric matrix, and wherein the first polymer matrix isdifferent from the second polymer matrix.
 4. The material of claim 3,wherein the first polymer matrix comprises a first thermoplasticmaterial and the second polymer matrix comprises a second thermoplasticmaterial.
 5. The material of claim 3, wherein the first polymer matrixis a thermoplastic material and the second polymer matrix material is athermosetting material.
 6. The material of claim 2, wherein the firstflakes comprise first fibers in a first polymer matrix and the secondflakes comprise fibers in a second polymeric material, wherein the firstfibers are different from the second fibers.
 7. The material of claim 1,comprising flakes of substrate.
 8. The material of claim 1, comprisingan adhesive.
 9. The material of claim 1, wherein the flakes of compositematerial comprise fibers in a thermoplastic polymer matrix, and whereinthe material is made by consolidating the flakes by the application ofheat, pressure, an adhesive, or a combination of two or more of thereof.10. A method for making an improve substrate, comprising: providing asubstrate; and applying a coating onto the substrate, the coatingcomprising flakes of composite material.
 11. The method of claim 10,comprising applying a coating that comprises a combination ofthermoplastic flakes and thermosetting flakes.
 12. The method of claim10, comprising applying a plurality of layers of coating on thesubstrate.
 13. The method of claim 10, comprising applying layers ofcoating onto the substrate including a first layer primarily comprisingthermoplastic flakes and a second layer primarily comprisingthermosetting flakes.
 14. The method of claim 10, wherein the coatingcomprises unidirectional flakes that are aligned with each other in thecoating.
 15. The method of claim 10, wherein the substrate has anattachment region and the method comprises coating primarily theattachment region of the substrate.
 16. A method for securing a firstconstruction member to a second construction member, comprising applyinga coating onto an attachment region of the first construction member,and applying a fastener onto the first construction member in the coatedattachment region to secure the first construction member to the secondconstruction member.
 17. An improved substrate, comprising: a substrate;and a coating on the substrate, the coating comprising a plurality offlakes of composite material.